AMOC collapse: Scientists issue open letter warning on catastrophic risk of Atlantic ocean circulation collapse

Risk of Collapse of Ocean Circulation (AMOC) underestimated: Continued greenhouse gas emissions could trigger a regional cooling around the North Atlantic warned the Icelandic Met Office

An Open Letter by Climate Scientists, including 3 Australian climate scientists, was presented to the Nordic Council of Ministers warning of AMOC collapse "risk has so far been greatly underestimated. Such an ocean circulation change would have devastating and irreversible impacts especially for Nordic countries, but also for other parts of the world."

Global impacts may include "a shift in tropical rainfall belts, reduced oceanic carbon dioxide uptake (and thus faster atmospheric increase) as well as major additional sea-level rise particularly along the American Atlantic coast, and an upheaval of marine ecosystems and fisheries"

Professor Stefan Rahmstorf did a presentation and handed over the open letter to the Arctic Council.

If you want to read a summary of the latest science read Professor Rahmstorf summary as the feature article in Oceanography: Is the Atlantic Overturning Circulation Approaching a Tipping Point? Published Online: April 10, 2024.

The abstract for this feature article reads:

The Atlantic Meridional Overturning Circulation has a major impact on climate, not just in the northern Atlantic but globally. Paleoclimatic data show it has been unstable in the past, leading to some of the most dramatic and abrupt climate shifts known. These instabilities are due to two different types of tipping points, one linked to amplifying feedbacks in the large-scale salt transport and the other in the convective mixing that drives the flow. These tipping points present a major risk of abrupt ocean circulation and climate shifts as we push our planet further out of the stable Holocene climate into uncharted waters.

Here is Professor Stefan Rahmstorf delivering a lecture in April 2024 on whether the Atlantic Overturning Circulation is approaching a tipping point. 

 

Prof. Rahmstorf discusses the danger of a major ocean circulation change  with massive climate impacts around the world. 

This lecture was held on the occasion of Rahmstorf being awarded the Alfred Wegener Medal for his scientific achievements, the most prestigious award of the European Geosciences Union EGU.

A peer-reviewed, open-access and fully referenced article (understandable for non-experts) on the same topic was published in Oceanography magazine the week before this lecture.

Are you concerned yet about the ClimateCrisis? You should be.

New Zealand research into past climate variability shows that disruption to the AMOC transmits and impacts the temperatures and climate in the Southern Hemisphere, according to researchers who published at the Conversation in June 2024, Weakening or collapse of a major Atlantic current has disrupted NZ’s climate in the past – and could do so again

Climate model experiments show the impact of past AMOC variability on surface temperature in the Southern Hemisphere. Shaun Eaves, CC BY-ND

The model simulations support our geological evidence, showing air and sea surface temperatures in New Zealand respond sensitively to changes in AMOC intensity. When the AMOC weakens and Europe cools, New Zealand and the southern mid-latitudes undergo warming, and vice versa. The models also indicate changes in the AMOC are transported rapidly, within decades, to New Zealand via shifting global wind systems. Changes in the AMOC disrupt the temperature gradient between the hemispheres, which is a key control on the strength of westerly wind belts in the southern hemisphere, between the latitudes of 40°S and 60°S where New Zealand is.

Yet Australia is still approving new thermal coal mines, gas projects. Including fracking the NT in the Beetaloo Basin endangering sensitive hydrology, First Nation culture and communities. The Federal Government is Subsidising to the tune of $1.5 billion the Darwin Middlearm industrial hub for LNG export on Larrakia country with another $400 million for extra infrastructure (pipelines?)

Don’t forget exported gas has 33% greater lifecycle emissions than coal according to the latest research.

References

Icelandic Met Office, Continued greenhouse gas emissions could trigger a regional cooling around the North Atlantic https://en.vedur.is/about-imo/news/continued-greenhouse-gas-emissions-could-trigger-a-regional-cooling-around-the-north-atlantic

Open Letter by Climate Scientists to the Nordic Council of Ministers, Reykjavik, October 2024 https://en.vedur.is/media/ads_in_header/AMOC-letter_Final.pdf

Stefan Rahmstorf, Is the Atlantic Overturning Circulation Approaching a Tipping Point?, Oceanography, (April 10, 2024) https://tos.org/oceanography/article/is-the-atlantic-overturning-circulation-approaching-a-tipping-point

The Conversation, 11 June 2024, Weakening or collapse of a major Atlantic current has disrupted NZ’s climate in the past – and could do so again https://theconversation.com/weakening-or-collapse-of-a-major-atlantic-current-has-disrupted-nzs-climate-in-the-past-and-could-do-so-again-231266

Climate Action Merribek, October 5 2024, John Englart, Tell Labor, Exported gas produces far worse emissions than coal https://climateactionmerribek.org/2024/10/05/tell-labor-exported-gas-produces-far-worse-emissions-than-coal/

Robert W. Howarth, 3 October 2024, The greenhouse gas footprint of liquefied natural gas (LNG) exported from the United States, Energy, Science and Engineering, https://doi.org/10.1002/ese3.1934